DDG/Trace Analysis

* Added mod-nodes
* Par and Memo nodes work now
* Added dependency tracking
* Added command line params
* Added side-by-side diff for traces (so we can inspect change propagation)
* Added framework for further analysis

Tracking of bound variables is broken since this merge, will be fixed soon. 

For help use: 

bin/visualization.sh --help 

Sample run: 

Single: bin/visualization.sh -a quicksort
Diff: bin/visualization.sh -a quicksort -d